GUZMAN, Rui Diaz de, Spanish-American historian, born in Paraguay in 1544. The date and place of his death are unknown. His father embarked for America in 1540 in the suite of Cabeza de Vaca. The son served at an early age against the Indians, under the command of his father; and, although in his writings he deplores the extermination of the natives and denounces the sanguinary policy of the conquerors, he showed little mercy toward them in the numerous conflicts in which he was engaged. The greater part of his life was passed in the province of Guayra, of which he became commander; but in this office he refused to acknowledge the supremacy of the governor of Paraguay, and was obliged to justify himself before the audience of Charcas. Aided by his notes and information gained from the conquerors, he undertook to relate the discovery and colonization of the Argentine provinces, under the title "Historia Argentina del descubrimiento poblacion y conquista de las provincias del Rio de la Plata." The dedication to the Duke of Medina bears date 25 July, 1612. In spite of its great merit, Guzman's work was not issued until De Angelis undertook the publication of the "Colleccion de obras y documentos relativos a la historia antigua y moderna de las provincias del Rio de la Plata, etc." (6 vols., Buenos Avres, 1836). It appears in the beginning of the first volume, accompanied by biographical researches of great interest. The work of Guzman has been copied by most historians that have written on the Argentine provinces. The narrative closes with 1575.